In the video encoding and decoding process, the inter-frame motion compensation prediction technology plays an important role in improving the encoding and decoding efficiency. The inter-frame motion compensation prediction technology refers to that: during the encoding and decoding process, a motion compensation is performed by using a motion vector obtained by a search, to implement the encoding and decoding operations.
At present, a motion vector search method adopted during motion vector estimation at a decoding end is to perform a search on the integral points in a limited range and a fine search on the sub-pixels around the found best integral point, to determine the corresponding motion vectors. For example, as shown in FIG. 1, firstly, eight half pixels 1 to 8 around are searched, and then, eight ¼ pixels a to h around the selected best half pixels are searched, to implement the search of the corresponding motion vectors. Alternatively, another motion vector search method, called three-step search (TSS), may be used. As shown in FIG. 2, the method is to select a search path according to a Sudoku search template in a certain search range. Specifically, the method includes: first, searching for the position matching degrees of nine path points in a larger range according to a search path template, selecting the best matching point; then, looking for and finding the best matching point of the nine path points in a smaller range according to the same search path template; and finally using the motion vector of the point as the motion vector obtained by the search.
The inventor finds at least the following problems in the prior art during the implementation of the invention.
The two motion vector search methods both have the following problems: the search range is large, and the search process is complex, lowering the encoding and decoding efficiency during encoding and decoding.